1. Field of the Invention
The present invention relates to a method and an apparatus for disassembling a lens-fitted photo film unit. More particularly, the present invention relates to a method and an apparatus for disassembling a lens-fitted photo film unit with increased efficiency.
2. Description Related to the Prior Art
U.S. Pat. No. 5,436,685 (corresponding to JP-A 3-200050) discloses a lens-fitted photo film unit, which is pre-loaded with photo film of a photo film cassette by operation in a factory. The lens-fitted photo film unit is constituted by a photo film containing unit, a front cover and a rear cover. The photo film containing unit accommodates the photo film. The front cover covers the front of the photo film containing unit. The rear cover covers the rear of the photo film containing unit. There are an exposure unit and a flash unit mounted on the photo film containing unit. The exposure unit incorporates a shutter mechanism and a taking lens. When all frames on the photo film are exposed, the lens-fitted photo film unit is forwarded to a photo laboratory, where the photo film cassette containing the photo film after exposures is removed from the lens-fitted photo film unit. The photo film is subjected to development and printing by use of the photo-finishing system available for any ordinary types of photo films. Photographic prints are produced and supplied to a user, to whom the photo film being developed is also returned.
There are various suggestions of recycling industrial products to protect the environment and reduce industrial wastes. There are two manners of recycling, including "regenerating" of material and "reusing" of parts. The regenerating is to withdraw molded parts or simply metal parts, to melt them, to obtain raw material from the melted parts, and to form molded parts or simply metal parts having a shape equal to their initial shape. The reusing is to withdraw unified parts in a combination of small elements, to select acceptable ones of them by checking their performance, and to transfer them to an assembly line together with the same unused parts. U.S. Pat. No. 5,615,395 (corresponding to JP-A 6-161042) discloses a recycling manner of the lens-fitted photo film unit. The photo film containing unit, the front cover and the rear cover are melted to obtain pellets of resin, and regenerated. The exposure unit is separated from the photo film containing unit, and reused. The flash unit is also reused. The flash unit is constituted by a printed circuit board, with which elements are connected, including circuit elements, the photo film, a synchro switch and the like. After the flash unit is removed from the photo film containing unit, a new dry battery is inserted in the flash unit for the reuse of the flash unit.
The lens-fitted photo film unit of the type incorporating the flash unit accommodates the battery as a power source. In an earlier model of this type, there is a bottom opening formed in the bottom of the lens-fitted photo film unit for insertion of the battery. A cardboard box or outer casing is used to package the lens-fitted photo film unit and also to close the bottom opening under the battery. In disassembly of this type of lens-fitted photo film unit, the battery can be easily separated after removal of the cardboard box and the front cover. There is a newer model of the flash built-in type, which has a cardboard belt or label of a small thickness instead of the cardboard box in consideration of reduction of the size of the lens-fitted photo film unit. But a problem arises in that the cardboard belt of a small width cannot close the bottom opening sufficiently under the battery. JP-A 8-328205 discloses a construction in which the rear cover has a bottom wall portion, which is protruded toward the front, for closing the bottom opening in the center of the photo film containing unit.
There has been a suggestion for reducing a cost required for recycling, for example by reducing the number of steps of the disassembly operation. However the exposure unit is separated from the photo film containing unit where the rear cover remains for the purpose of the exposure unit. The process of separation of the exposure unit must be safe enough to avoid damaging the exposure unit. High precision in the disassembly operation is required, to complicate the disassembly apparatus.
The lower side of the battery is covered and supported by a portion of the rear cover. Thus it is extremely difficult for an automatic apparatus to remove the battery in the state after removal of the front cover. Also the battery has a cylindrical shape, which is difficult for the automatic apparatus safely to grasp. Furthermore it is likely that a bottom lid located under the photo film cassette, or broken plastic pieces created by shock during disassembly or transport are dropped or scattered to disorder or break the automatic apparatus. Efficiency in the disassembly operation is lowered.